Non-metallic vertebrae bend restrictor and vertebrae end piece

ABSTRACT

A non-metallic clip connection system includes a non-metallic clip having a substantially rectangular base portion, a first longitudinal flared wing portion, and a second longitudinal flared wing portion, wherein a plurality of edges of the clip along a path of insertion are beveled or radiused. The non-metallic clip connection system also includes a first non-metallic member having a first portion of a non-metallic clip receiver and a second non-metallic member having a second portion of the non-metallic clip receiver. The first non-metallic member is secured to the second non-metallic member by inserting the non-metallic clip in the non-metallic clip receiver. A non-metallic vertebrae bend restrictor and a non-metallic vertebrae end piece may use a non-metallic clip connection system.

CROSS-REFRENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/718,195, filed on Sep. 28, 2017, which is a bypasscontinuation of PCT International Application PCT/US2017/014951, filedon Jan. 25, 2017, both of which are hereby incorporated by reference intheir entirety.

BACKGROUND OF THE INVENTION

Conventional energy exploration, production, and workover uses one ormore rigs, platforms, work vessels, or combinations thereof to performdrilling, completion, workover, or production operations. Theseoperations may require one or more flexible flow lines, flying leads,mux lines, umbilicals, cables, or other flexible conduits. For example,in offshore applications, these flexible conduits may be used to connectcertain surface-based equipment disposed on a platform above thewaterline to subsea equipment in the water. These flexible conduits formthe connective medium and may include one or more of electrical powerand signal cabling, hydraulic power and activation cabling, chemicalinjection cabling, communications cabling, and robotic-operated vehiclecabling. The flexible conduits are exposed to high tensile bending loadsduring installation and, once disposed in the water, are subjected tointernal pressure, hydrostatic loading, high tensile loading and fatiguedue to motion of the water or equipment, and loads caused directly orindirectly by unplanned activities. Conventional vertebrae bendrestrictors are used to encase and protect one or more flexible conduitsin a manner that is similar to the way the vertebrae bones of the humanbody encase and protect the spinal cord. Conventional vertebrae bendrestrictors prevent flexible conduits from bending beyond a rated amountof bend radius under a rated amount of force, thereby protecting theflexible conduit from damage.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of one or more embodiments of the presentinvention, a non-metallic clip connection system includes a non-metallicclip having a substantially rectangular base portion, a firstlongitudinal flared wing portion, and a second longitudinal flared wingportion, wherein a plurality of edges of the clip along a path ofinsertion are beveled or radiused. The non-metallic clip connectionsystem also includes a first non-metallic member having a first portionof a non-metallic clip receiver and a second non-metallic member havinga second portion of the non-metallic clip receiver. The firstnon-metallic member is secured to the second non-metallic member byinserting the non-metallic clip in the non-metallic clip receiver.

According to one aspect of one or more embodiments of the presentinvention, a non-metallic vertebrae bend restrictor includes a firstnon-metallic half member, a second non-metallic half member, a firstnon-metallic clip, and a second non-metallic clip. The firstnon-metallic half member includes a first half of a ball portion, afirst half of a socket portion, a first half of a first non-metallicclip receiver, a first half of a second non-metallic clip receiver, anda first half of a cavity. The second non-metallic half member includes asecond half of the ball portion, a second half of the socket portion, asecond half of the first non-metallic clip receiver, a second half ofthe second non-metallic clip receiver, and a second half of the cavity.The first non-metallic half member is secured to the second non-metallichalf member by inserting the first non-metallic clip in the firstnon-metallic clip receiver and inserting the second non-metallic clip inthe second non-metallic clip receiver.

According to one aspect of one or more embodiments of the presentinvention, a non-metallic vertebrae end piece includes a firstnon-metallic half member, a second non-metallic half member, a firstnon-metallic clip, and a second non-metallic clip. The firstnon-metallic half member includes a first half of a socket portion, afirst half of a first non-metallic clip receiver, a first half of asecond non-metallic clip receiver, and a first half of a cavity. Thesecond non-metallic half member includes a second half of the socketportion, a second half of the first non-metallic clip receiver, a secondhalf of the second non-metallic clip receiver, and a second half of thecavity. The first non-metallic half member is secured to the secondnon-metallic half member by inserting the first non-metallic clip in thefirst non-metallic clip receiver and inserting the second non-metallicclip in the second non-metallic clip receiver.

Other aspects of the present invention will be apparent from thefollowing description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B, 1C, 1D, 1E, 1F, 1G, and 1H show an interior-facingelevation view, an exterior-facing elevation view, a left-side elevationview, a right-side elevation view, a top plan view, a bottom plan view,an interior-facing isometric view, and an exterior-facing isometric viewrespectively of a non-metallic member of a non-metallic vertebrae bendrestrictor in accordance with one or more embodiments of the presentinvention.

FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, and 2H show an interior-facingelevation view, an exterior-facing elevation view, a left-side elevationview, a right-side elevation view, a top plan view, a bottom plan view,an interior-facing isometric view, and an exterior-facing isometric viewrespectively of a non-metallic clip of a non-metallic vertebrae bendrestrictor in accordance with one or more embodiments of the presentinvention.

FIGS. 3A, 3B, 3C, and 3D show an elevation view, an isometric view, atop plan view, and a bottom plan view respectively of an optionalretention screw for a non-metallic clip of a non-metallic vertebrae bendrestrictor in accordance with one or more embodiments of the presentinvention.

FIGS. 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H, and 4I show two non-metallicmembers of a non-metallic vertebrae bend restrictor coming together,insertion of a first non-metallic clip and optional retention screws,insertion of a second non-metallic clip and optional retention screws, afront or rear facing elevation view assembled, a left-side or right-sideelevation view assembled, a top plan view assembled, a bottom plan viewassembled, a top-facing isometric view assembled, and a bottom facingisometric view assembled respectively of a non-metallic vertebrae bendrestrictor in accordance with one or more embodiments of the presentinvention.

FIG. 5A, 5B, 5C, 5D, 5E, 5F, 5G, and 5H show an interior-facingelevation view, an exterior-facing elevation view, a left-side elevationview, a right-side elevation view, a top plan view, a bottom plan view,an interior-facing isometric view, and an exterior-facing isometric viewrespectively of a non-metallic member of a non-metallic vertebrae endpiece in accordance with one or more embodiments of the presentinvention.

FIGS. 6A, 6B, 6C, and 6D show two non-metallic members of a non-metallicend piece coming together, insertion of a first non-metallic clip andoptional retention screws, insertion of a second non-metallic clip andoptional retention screws, and a top-facing isometric view assembled ofa non-metallic vertebrae end piece in accordance with one or moreembodiments of the present invention.

FIG. 7 shows an environmental view of a non-metallic vertebrae bendrestrictor installation in accordance with one or more embodiments ofthe present invention.

FIG. 8A, 8B, 8C, 8D, and 8E show two non-metallic members of anon-metallic clip connection system coming together, insertion of afirst non-metallic clip, insertion of a second non-metallic clip, and atop-facing isometric view assembled of a non-metallic clip connectionsystem in accordance with one or more embodiments of the presentinvention.

FIG. 9 shows a top plan view of a clip connection system as part of avertebrae bend restrictor in accordance with one or more embodiments ofthe present invention.

DETAILED DESCRIPTION OF THE INVENTION

One or more embodiments of the present invention are described in detailwith reference to the accompanying figures. For consistency, likeelements in the various figures are denoted by like reference numerals.In the following detailed description of the present invention, specificdetails are set forth in order to provide a thorough understanding ofthe present invention. In other instances, well-known features to one ofordinary skill in the art are not described to avoid obscuring thedescription of the present invention.

Conventional vertebrae bend restrictors are used in virtually alloffshore drilling, production, and workover rigs as well as wind farmsand are well known in the art. A conventional vertebrae bend restrictorincludes a plurality of vertebrae, each comprised of a first member anda second member that connect around a portion of the conduit and areconnected by metallic nuts and bolts typically comprised of steel, snapconnections, straps, or zip ties. Conventional vertebrae bendrestrictors are assembled in an additive manner such that once a firstvertebrae is installed, a socket portion of a second vertebrae encases aball portion of the first vertebrae and restricts movement between thefirst and second vertebrae to a rated amount of bend radius under arated amount of force. This process is repeated until the requirednumber of vertebrae is installed to encase and protect the conduit.

However, the metal content of conventional vertebrae bend restrictors isprone to corrosion unless the metal components are comprised ofcorrosion resistant alloys, coated in a corrosion resistant coating, oruse cathodic protection. While corrosion resistant alloys are effective,they are prohibitively expensive and are typically not used. Coating themetal components in a corrosion resistant coating is also expensive andremains prone to failure over time because of one or more of issuesrelated to the coating composition, the application of the coatingcomposition, or wear and tear. If a failure occurs, a first member and asecond member of a vertebrae bend restrictor may detach and the conduitmay bend beyond the rated amount of bend radius, resulting in damage orcomplete loss of the conduit.

Cathodic protection attempts to control the corrosion of the metalsurfaces of the conventional vertebrae bend restrictor by converting theanodic sites of the metal surfaces to cathodic sites by supplyingelectrical current from an alternate source. Typically, this takes theform of galvanic anodes, which are more active than steel. In thissacrificial system, the galvanic anodes sacrifice themselves to protectthe steel nuts and bolts from corrosion. However, cathodic protection isvery expensive, requires maintenance, and is also prone to failure overtime. If a failure occurs, a first member and a second member of avertebrae bend restrictor may detach and the conduit may bend beyond arated amount of bend radius, resulting in damage or complete loss of theconduit. While snap connections, straps, and zip ties typically includeless metal content, they too suffer from a number of issues thatcomplicate their use. The snap connections, straps, and zip ties do notprovide tight connectivity, are unreliable, and are prone to failureover time from wear and tear.

Accordingly, in one or more embodiments of the present invention, anon-metallic vertebrae bend restrictor and a non-metallic vertebrae endpiece use a non-metallic clip connection system that does not requirecoating or cathodic protection and reduces the expense of manufacturing,installing, and maintaining the vertebrae bend restrictor system.Advantageously, the non-metallic vertebrae bend restrictor andnon-metallic vertebrae end piece are less expensive to manufacture,easier and less expensive to install, do not require substantivemaintenance, and provide improved protection for flexible conduits.

FIG. 1A shows an interior-facing elevation view of a non-metallic member100 of a non-metallic vertebrae bend restrictor (not shown) inaccordance with one or more embodiments of the present invention. Twoidentical or substantially identical non-metallic members 100 may bejoined together around a flexible conduit (not shown) and secured to oneanother with a non-metallic clip connection system (not shown) to form anon-metallic vertebrae bend restrictor (not shown) in accordance withone or more embodiments of the present invention. One or morenon-metallic vertebrae bend restrictors (not shown) may be used asnecessary to encase and protect the flexible conduit (not shown). One ofordinary skill in the art will recognize that two substantiallyidentical non-metallic members 100 may vary somewhat from one another inshape, size, and markings based on an application or design inaccordance with one or more embodiments of the present invention.

Non-metallic member 100 may include, generally, a ball portion 105 and asocket portion 110 of the non-metallic vertebrae bend restrictor (notshown). Ball portion 105 may include a protruding rib portion 130 thatis configured to fit and move within a rib receiver portion 135 ofanother non-metallic vertebrae bend restrictor (not shown). A bossportion 185 may include a first portion of a first non-metallic clipreceiver 115 on the left side of member 100 and a first portion of asecond non-metallic clip receiver 120 on the right side of member 100such that, when two non-metallic members 100 are joined together, form afirst non-metallic clip receiver (not shown) and a second non-metallicclip receiver (not shown) that are configured to receive non-metallicclips (not shown). Boss portion 185 may include an optional boss clipstop portion 180 to prevent over insertion of the non-metallic clips(not shown) and one or more optional boss retention screw receivers 175that may be used to provide additional retention force to the clips (notshown). Each of first portion of first non-metallic clip receiver 115and first portion of second non-metallic clip receiver 120 may include aportion of a clip retention feature receiver 117 such that, when twonon-metallic members 100 are joined together, form a first clipretention feature receiver (not shown) and a second clip retentionfeature receiver (not shown) that are configured to receive a clipretention feature (not shown) of the non-metallic clips (not shown) toprevent ejection of the non-metallic clips (not shown).

Non-metallic member 100 may include a portion of a cavity (of which 125denotes a centerline therethrough) that extends from the top through tothe bottom of member 100. Cavity 125 may have an inner diameter, ID,suitable to encase a flexible conduit (not shown). In certainembodiments, the ID may be slightly larger than the conduit. In otherembodiments, the ID may be substantially larger than the conduit. One ofordinary skill in the art will recognize that the ID may vary based onan application or design in accordance with one or more embodiments ofthe present invention. Portion of cavity 125 may include a flaredportion 140 that extends from socket portion 110 to the bottom of member100 and a flared portion 142 that extends from ball portion 105 to thetop of member 100.

Non-metallic member 100 may include one or more optional ball alignmentand shear protrusions 145 and one or more optional receivers 150 thatmay be used to align ball portions 105 of two non-metallic members 100during assembly of a non-metallic vertebrae bend restrictor (not shown)and take shear loads once assembled. In certain embodiments, ballalignment and shear protrusion 145 may have a substantially cylindricalshape and a diameter that may vary based on an application or design andball alignment and shear protrusion receiver 150 may vary accordingly.One of ordinary skill in the art will recognize that the size, shape,number, and location of ball alignment and shear protrusion 145 andreceiver 150 may vary in accordance with one or more embodiments of thepresent invention.

Non-metallic member 100 may include an optional socket alignment andshear protrusion 155 and an optional socket alignment and shearprotrusion receiver 160 that may be used to align socket portions 110 oftwo non-metallic members 100 during assembly of a non-metallic vertebraebend restrictor (not shown) and take shear loads once assembled. Incertain embodiments, socket alignment and shear protrusion 155 may havea substantially cylindrical shape and have a diameter that may varybased on an application or design and socket alignment and shearprotrusion receiver 160 may vary accordingly. One of ordinary skill inthe art will recognize that the size, shape, number, and location ofsocket alignment and shear protrusion 155 and receiver 160 may vary inaccordance with one or more embodiments of the present invention. Ballalignment and shear protrusion 145 and socket alignment and shearprotrusion 155 may preferably be disposed on opposing sides ofnon-metallic half member 100 as shown in the figure or may be disposedon the same side in other embodiments.

Non-metallic member 100 may include one or more optional boss alignmentand shear protrusions 165 and one or more optional boss alignment andshear protrusion receivers 170 that may be used to align the bossportions 185 of two non-metallic members 100 during assembly of anon-metallic vertebrae bend restrictor (not shown) and take shear loadsonce assembled. In certain embodiments, boss alignment and shearprotrusion 165 may have a substantially trapezoidal shape and have alength and width that may vary based on an application or design andboss alignment and shear protrusion receiver 170 may vary accordingly.One of ordinary skill in the art will recognize that the size, shape,number, and location of boss alignment and shear protrusion 165 andreceiver 170 may vary in accordance with one or more embodiments of thepresent invention. Boss alignment and shear protrusion 165 may bedisposed on either side of non-metallic half member 100.

Continuing, FIG. 1B shows an exterior-facing elevation view of anon-metallic member 100 of a non-metallic vertebrae bend restrictor (notshown) in accordance with one or more embodiments of the presentinvention. In the view, an exterior view of optional boss retentionscrew receivers 175 is shown, where, after joining of two non-metallicmembers (not shown) with two non-metallic clips (not shown), optionalretention screws (not shown) may be inserted from the exterior side ofnon-metallic member 100 and come to rest in optional clip retentionscrew receivers (not shown) of the clips (not shown) to provideadditional retention force to the clips (not shown). Also in this view,a rib portion 130 and a boss portion 185 are shown. Continuing, FIG. 1Cshows a left-side elevation view and FIG. 1D shows a right-sideelevation view of a non-metallic member 100 of a non-metallic vertebraebend restrictor (not shown) in accordance with one or more embodimentsof the present invention. In these views, ball alignment and shearprotrusions 145, socket alignment and shear protrusions 155, and bossalignment and shear protrusions 165 are shown. FIGS. 1C and FIG. 1D arealso representative of how two non-metallic members 100 would beoriented to face and align with one another prior to being joinedtogether around a flexible conduit.

Continuing, FIG. 1E shows a top plan view of a non-metallic member 100of a non-metallic vertebrae bend restrictor (not shown) in accordancewith one or more embodiments of the present invention. In this view, theshape of a first portion of first non-metallic clip receiver 115 and theshape of a first portion of second non-metallic clip receiver 120 isshown as well as optional boss clip stop portion 180 that prevents overinsertion of the clips (not shown). In certain embodiments, anon-metallic member 100 may include one or more push ports 190 that maybe used to push a clip (not shown) out of the receiver 115. In addition,a portion of cavity 125, which encases the flexible conduit (not shown)is shown. Continuing, FIG. 1F shows a bottom plan view a non-metallicmember 100 of a non-metallic vertebrae bend restrictor (not shown) inaccordance with one or more embodiments of the present invention. Inthis view, flared portion 140 is shown that extends from socket portion110 to the bottom of member 100 that allows for clearance.

Continuing, FIG. 1G shows an interior-facing isometric view of anon-metallic member 100 of a non-metallic vertebrae bend restrictor (notshown) in accordance with one or more embodiments of the presentinvention. In this view, a portion of clip retention feature receiver117 is shown. When two non-metallic members 100 are joined together, twoportions 117 form a clip retention feature receiver (not shown) that isconfigured to receive a clip retention feature (not shown) of a clip(not shown) to promote retention of the clip (not shown). Continuing,FIG. 1H shows an exterior-facing isometric view of a non-metallic member100 of a non-metallic vertebrae bend restrictor (not shown) inaccordance with one or more embodiments of the present invention.

In certain embodiments, non-metallic member 100 may be composed of apolyurethane polymer. In other embodiments, non-metallic member 100 maybe composed of acetyl, high density polypropylene, thermoset plastic,carbon reinforced plastic, thermoset urethane, or fiberglass reinforcedurethane. In still other embodiments, non-metallic member 100 may becomposed of other non-metallic high modulus materials. One of ordinaryskill in the art will recognize that any non-metallic high modulusmaterial suitable for encasing and protecting a flexible conduit (notshown) may be used in accordance with one or more embodiments of thepresent invention.

FIG. 2A shows an interior-facing elevation view of a non-metallic clip200 of a non-metallic vertebrae bend restrictor (not shown) inaccordance with one or more embodiments of the present invention.Non-metallic clip 200 may include a substantially rectangular baseportion 205, a first longitudinal flared wing portion 210, and a secondlongitudinal flared wing portion 215. Continuing, FIG. 2B shows anexterior-facing elevation view of a non-metallic clip 200 of anon-metallic vertebrae bend restrictor (not shown) in accordance withone or more embodiments of the present invention. In this view, clipretention feature 220 is shown that may be used to promote retention ofclip 200 after assembly. Continuing, FIG. 2C shows a left-side elevationview of a non-metallic clip 200 of a non-metallic vertebrae bendrestrictor (not shown) in accordance with one or more embodiments of thepresent invention. In this view, an optional clip retention screwreceiver 225 is shown. During assembly of a non-metallic vertebrae bendrestrictor (400 of FIG. 4), once two non-metallic members (100 ofFIG. 1) are joined together, one or more clips 200 may be inserted intoone or more non-metallic clip receivers (410 of FIG. 4). One or moreoptional retention screws (300 of FIG. 3) may be passed through optionalboss retention screw receivers (175 of FIG. 1) of a non-metallic member(100 of FIG. 1) and into one or more optional clip retention screwreceivers 225 of each clip 200 to further secure clip 200 into place.Continuing, FIG. 2D shows a right-side elevation view of a non-metallicclip 200 of a non-metallic vertebrae bend restrictor (not shown) inaccordance with one or more embodiments of the present invention. Inthis view, another optional clip retention screw receiver 225 disposedon the opposing side of clip 200 is shown.

Continuing, FIG. 2E shows a top plan view of a non-metallic clip 200 ofa non-metallic vertebrae bend restrictor (not shown) in accordance withone or more embodiments of the present invention. In this view, topportions of the substantially rectangular base portion 205, clipretention feature 220, first longitudinal flared wing portion 210, andsecond longitudinal flared wing portion 215 are shown. In certainembodiments, clip retention feature 220 may be a half-cylinder withradius blending. In other embodiments, clip retention feature 220 may becomprised of a plurality of smaller retention features (not shown). Oneof ordinary skill in the art will recognize that clip retention feature220 may vary in number, size, shape, fit, and length of features basedon an application or design in accordance with one or more embodimentsof the present invention. While the fit and form may vary, the functionremains the same. First and second longitudinal flared wing portions210, 215 may have substantially flat exterior facing surfaces and flaredinterior facing surfaces. Continuing, FIG. 2F shows a bottom plan viewof a non-metallic clip 200 of a non-metallic vertebrae bend restrictor(not shown) in accordance with one or more embodiments of the presentinvention. One or more bottom facing edges 235 may be beveled 240 orradiused (not shown) to assist with insertion of clip 200 into a clipreceiver (not shown). Continuing, FIG. 2G shows an interior-facingisometric view of a non-metallic clip 200 of a non-metallic vertebraebend restrictor (not shown) in accordance with one or more embodimentsof the present invention. In this view, interior longitudinal edges andbottom facing edges are beveled 240 or radiused (not shown) to assistwith insertion of clip 200 into a clip receiver (not shown). Inaddition, an optional clip stop retention screw receiver 225 is shown.Continuing, FIG. 2H shows an exterior-facing isometric view of anon-metallic clip 200 of a non-metallic vertebrae bend restrictor (notshown) in accordance with one or more embodiments of the presentinvention. In this view, exterior longitudinal edges are beveled 240 orradiused (not shown) to assist with insertion of clip 200 into a clipreceiver (not shown). In addition, another optional clip stop retentionscrew receiver 225 is shown.

In one or more embodiments of the present invention, two non-metallicclips 200 may be used as part of a non-metallic vertebrae bendrestrictor (not shown). One of ordinary skill in the art will recognizethat the size, shape, and number of clips 200 used may vary based on anapplication or design in accordance with one or more embodiments of thepresent invention. In certain embodiments, non-metallic clip 200 may becomposed of a polyurethane polymer. In other embodiments, non-metallicclip 200 may be composed of acetyl, high density polypropylene,thermoset plastic, carbon reinforced plastic, thermoset urethane, orfiberglass reinforced urethane. In still other embodiments, non-metallicclip 200 may be composed of other non-metallic high modulus material.While it is preferable that non-metallic clip 200 be composed of thesame material as the non-metallic members (100 of FIG. 1) that is joinstogether, one of ordinary skill in the art will recognize that anysuitable non-metallic high modulus material may be used in accordancewith one or more embodiments of the present invention.

FIGS. 3A shows an elevation view of an optional retention screw 300 fora non-metallic clip of a non-metallic vertebrae bend restrictor inaccordance with one or more embodiments of the present invention. In oneor more embodiments of the present invention, one or more optionalretention screws 300 may be used to further secure clips (200 of FIG. 2)into place after assembly of a non-metallic vertebrae bend restrictor(400 of FIG. 4). Continuing, FIG. 3B shows a top facing isometric viewof an optional retention screw 300 in accordance with one or moreembodiments of the present invention. Continuing, FIG. 3C shows a topplan view of an optional retention screw 300 in accordance with one ormore embodiments of the present invention. Continuing, FIG. 3D shows abottom plan view of an optional retention screw 300 in accordance withone or more embodiments of the present invention. In certainembodiments, optional retention screw 300 may be composed of nylon. Inother embodiments, optional retention screw 300 may be composed of othernon-metallic material. One of ordinary skill in the art will recognizethat any suitable non-metallic material may be used in accordance withone or more embodiments of the present invention.

FIG. 4A shows two non-metallic members 100 a, 100 b of a non-metallicvertebrae bend restrictor (partially shown) coming together duringassembly in accordance with one or more embodiments of the presentinvention. An interior face of a first non-metallic member 100 a mayface and align with an interior face of a second non-metallic member 100b around a flexible conduit (not shown). Optional ball alignment andshear protrusion 145 a of first non-metallic member 100 a may align andinsert into an optional ball alignment and shear protrusion receiver(not shown) of second non-metallic member 100 b. Similarly, an optionalball alignment and shear protrusion (not shown) of second non-metallicmember 100 b may align and insert into optional ball alignment and shearprotrusion receiver 150 a of first non-metallic member 100 a. Optionalsocket alignment and shear protrusion 155 a of first non-metallic member100 a may align and insert into an optional socket alignment and shearprotrusion receiver (not shown) of second non-metallic member 100 b.Similarly, an optional socket alignment and shear protrusion (not shown)of second non-metallic member 100 b may align and insert into optionalsocket alignment and shear protrusion receiver 160 a of firstnon-metallic member 100 a. One or more optional boss alignment and shearprotrusions 165 a of first non-metallic member 100 a may align andinsert into one or more optional boss alignment and shear protrusionreceivers (not shown) of second non-metallic member 100 b. Similarly,one or more optional boss alignment and shear protrusions (not shown) ofsecond non-metallic member 100 b may align and insert into one or moreoptional boss alignment and shear protrusion receivers 170 a of firstnon-metallic member 100 a.

Continuing, FIG. 4B shows insertion of a first non-metallic clip 200 aand optional retention screws 300 a, 300 b as part of assembly of thenon-metallic vertebrae bend restrictor (partially shown) in accordancewith one or more embodiments of the present invention. After joiningfirst non-metallic member 100 a to second non-metallic member 100 b, afirst non-metallic clip 200 a may be inserted into a first non-metallicclip receiver 410 a. Once clip 200 a is fully inserted, one or moreoptional clip retention screws 300 a, 300 b may be secured through bossretention screw receivers 175 into optional clip retention screwreceiver 225 of clip 200 a. Continuing, FIG. 4C shows insertion of asecond non-metallic clip 200 b and optional retention screws 300 c, 300d as part of assembly of the non-metallic vertebrae bend restrictor(partially shown) in accordance with one or more embodiments of thepresent invention. A second non-metallic clip 200 b may be inserted intoa second non-metallic clip receiver 410 b. Once clip 200 b is fullyinserted, one or more optional clip retention screws 300 c, 300 d may besecured through boss retention screw receivers 175 into optional clipretention screw receiver 225 of clip 200 a. Continuing, FIG. 4D shows afront or rear facing elevation view of the assembled non-metallicvertebrae bend restrictor 400 in accordance with one or more embodimentsof the present invention. Continuing, FIG. 4E shows a left-side orright-side facing elevation view of the assembled non-metallic vertebraebend restrictor 400 in accordance with one or more embodiments of thepresent invention. Continuing, FIG. 4F shows a top plan view of theassembled non-metallic vertebrae bend restrictor 400 in accordance withone or more embodiments of the present invention. Continuing, FIG. 4Gshows a bottom plan view of the assembled non-metallic vertebrae bendrestrictor 400 in accordance with one or more embodiments of the presentinvention. Continuing, FIG. 4H shows a top-facing isometric view of theassembled non-metallic vertebrae bend restrictor 400 in accordance withone or more embodiments of the present invention. Continuing, FIG. 4Ishows a bottom-facing isometric view of the assembled non-metallicvertebrae bend restrictor 400 in accordance with one or more embodimentsof the present invention.

FIG. 5A shows an interior-facing elevation view of a non-metallic member500 of a non-metallic vertebrae end piece (600 of FIG. 6) in accordancewith one or more embodiments of the present invention. Two identical orsubstantially identical non-metallic members 500 may be joined togetheraround a flexible conduit (not shown) and secured to one another with anon-metallic clip connection system (not shown) to form a non-metallicvertebrae end piece (600 of FIG. 6) in accordance with one or moreembodiments of the present invention. One of ordinary skill in the artwill recognize that two substantially identical non-metallic members 500may vary somewhat from one another in shape, size, and markings based onan application or design in accordance with one or more embodiments ofthe present invention.

In certain embodiments, a plurality of non-metallic vertebrae bendrestrictors (400 of FIG. 4) may be used to encase and protect a flexibleconduit (not shown). At a terminal end of the non-metallic vertebraebend restrictor installation, a non-metallic vertebrae end piece (600 ofFIG. 6) may be used to create an end cap termination. One of ordinaryskill in the art will recognize that non-metallic member 500 of anon-metallic vertebrae end piece (600 of FIG. 6) may be substantiallyidentical to non-metallic member (100 of FIG. 1) of a non-metallicvertebrae bend restrictor (400 of FIG. 4) with ball portion (105 ofFIG. 1) removed, thus allowing for use of non-metallic end piece (600 ofFIG. 6) as an end piece in a chain of non-metallic vertebrae bendrestrictors (400 of FIG. 4).

Continuing, FIG. 5B shows an exterior-facing elevation view of anon-metallic member 500 of a non-metallic vertebrae end piece (600 ofFIG. 6) in accordance with one or more embodiments of the presentinvention. Continuing, FIG. 5C shows a left-side elevation view of anon-metallic member 500 of a non-metallic vertebrae end piece (600 ofFIG. 6) in accordance with one or more embodiments of the presentinvention. Continuing, FIG. 5D shows a right-side elevation view of anon-metallic vertebrae end piece (600 of FIG. 6) in accordance with oneor more embodiments of the present invention.

Continuing, FIG. 5E shows a top plan view of a non-metallic member 500of a non-metallic vertebrae end piece (600 of FIG. 6) in accordance withone or more embodiments of the present invention. Non-metallic member500 of non-metallic vertebrae end piece (600 of FIG. 6) differs fromnon-metallic member (100 of FIG. 1) of non-metallic vertebrae bendrestrictor in that non-metallic member 500 has a flat planar surface 510where non-metallic member (100 of FIG. 1) has the ball portion (105 ofFIG. 1). Continuing, FIG. 5F shows a bottom plan view of a non-metallicmember 500 of a non-metallic vertebrae end piece (600 of FIG. 6) inaccordance with one or more embodiments of the present invention.

Continuing, FIG. 5G shows an interior-facing isometric view of anon-metallic member 500 of a non-metallic vertebrae end piece (600 ofFIG. 6) in accordance with one or more embodiments of the presentinvention. Continuing, FIG. 5H shows an exterior-facing isometric viewof a non-metallic member 500 of a non-metallic vertebrae end piece (600of FIG. 6) in accordance with one or more embodiments of the presentinvention.

In certain embodiments, non-metallic member 500 may be composed of apolyurethane polymer. In other embodiments, non-metallic member 500 maybe composed of acetyl, high density polypropylene, thermoset plastic,carbon reinforced plastic, thermoset urethane, or fiberglass reinforcedurethane. In still other embodiments, non-metallic member 500 may becomposed of other non-metallic high modulus materials. One of ordinaryskill in the art will recognize that any non-metallic high modulusmaterial suitable for encasing and protecting a flexible conduit (notshown) may be used in accordance with one or more embodiments of thepresent invention.

FIG. 6A shows two non-metallic members 500 a, 500 b of a non-metallicvertebrae end piece (partially shown) coming together during assembly inaccordance with one or more embodiments of the present invention. Aninterior face of a first non-metallic member 500 a may face and alignwith an interior face of a second non-metallic member 500 b around aflexible conduit (not shown). Optional socket alignment and shearprotrusion 155 a of first non-metallic member 500 a may align and insertinto an optional socket alignment and shear protrusion receiver (notshown) of second non-metallic member 500 b. Similarly, an optionalsocket alignment and shear protrusion (not shown) of second non-metallicmember 500 b may align and insert into optional socket alignment andshear protrusion receiver 160 a of first non-metallic -member 500 a. Oneor more optional boss alignment and shear protrusions 165 a of firstnon-metallic member 500 a may align and insert into one or more optionalboss alignment and shear protrusion receivers (not shown) of secondnon-metallic member 500 b. Similarly, one or more optional bossalignment and shear protrusions (not shown) of second non-metallicmember 500 b may align and insert into one or more optional bossalignment and shear protrusion receivers 170 a of first non-metallicmember 500 a. Optional socket alignment and shear protrusions 155 a andoptional boss alignment and shear protrusions 165 a may take shear loadsonce assembled.

Continuing, FIG. 6B shows insertion of a first non-metallic clip 200 aand optional retention screws 300 a, 300 b as part of assembly of thenon-metallic vertebrae end piece (partially shown) in accordance withone or more embodiments of the present invention. After joining firstnon-metallic member 500 a to second non-metallic member 500 b, a firstnon-metallic clip 200 a may be inserted into a first non-metallic clipreceiver 410 a. Once clip 200 a is fully inserted, one or more optionalclip retention screws 300 a, 300 b may be secured through boss retentionscrew receivers 175 into optional clip retention screw receiver 225 ofclip 200 a. Continuing, FIG. 6C shows insertion of a second non-metallicclip 200 b and optional retention screws 300 c, 300 d as part ofassembly of the non-metallic vertebrae end piece (partially shown) inaccordance with one or more embodiments of the present invention. Asecond non-metallic clip 200 b may be inserted into a secondnon-metallic clip receiver 410 b. Once clip 200 b is fully inserted, oneor more optional clip retention screws 300 c, 300 d may be securedthrough boss retention screw receivers 175 into optional clip retentionscrew receiver 225 of clip 200 a. Continuing, FIG. 6D shows a top-facingisometric view of the assembled non-metallic vertebrae end piece 600 inaccordance with one or more embodiments of the present invention.

FIG. 7 shows an environmental view of a non-metallic vertebrae bendrestrictor installation 700 in accordance with one or more embodimentsof the present invention. A number of vertebrae bend restrictors 400a-400 i may be used to encase a flexible conduit (not shown). In thisview, a plurality of vertebrae bend restrictors 400 a-400 i are shownwith a non-metallic vertebrae end piece 600 that creates an end captermination disposed on a first distal end. On a second distal end, aflange 710 may be used to provide fixed mechanical termination. Eachadjacent pair of vertebrae bend restrictors 400 restrict the amount ofbend between the vertebrae and together as an installation 700 allow forthe bending of the flexible conduit (not shown) without bending anyparticular segment of the flexible conduit (not shown) beyond its ratedamount of bend radius.

One of ordinary skill in the art will recognize that the non-metallicclip connection system of the non-metallic vertebrae bend restrictor(400 of FIG. 4) and the non-metallic vertebrae end piece (600 of FIG. 6)may be used in other applications in which non-metallic members ofdifferent shapes and sizes may be joined together with one or morenon-metallic clips.

FIG. 8A shows a first non-metallic member 810 comprising a first portion815 of a non-metallic clip receiver (not independently shown) and asecond non-metallic member 820 comprising a second portion 825 of thenon-metallic clip receiver (not independently shown). The shape and sizeof the exterior of the first non-metallic member 810, shown in dashedlines, may vary based on an application or design. Similarly, the shapeand size of the exterior of the second non-metallic member 820, alsoshown in dashed lines, may vary based on an application or design. Assuch, a non-metallic clip connection system may include one or morenon-metallic clip receivers (not independently illustrated) and one ormore non-metallic clips (not shown) that may be used to join togethernon-metallic members (not shown) of any shape or size. One of ordinaryskill in the art will recognize that the shape and size of thenon-metallic members (not shown) may vary based on an application ordesign in accordance with one or more embodiments of the presentinvention.

Continuing, FIG. 8B shows first non-metallic member 810 brought togetherand aligned with second non-metallic member 820. The first portion (815of FIG. 8A) of first non-metallic member 810 and the second portion (825of FIG. 8A) of second non-metallic member 820 form a non-metallic clipreceiver 830 configured to receive a non-metallic clip (not shown). Thenon-metallic clip receiver 830 may have a shape and size configured toreceive a non-metallic clip (not shown) with an interference fit.Continuing, FIG. 8C shows a non-metallic clip 200 prior to insertioninto the non-metallic clip receiver 830 formed by first non-metallicmember 810 and second non-metallic member 820. Continuing, FIG. 8D showsthe non-metallic clip 200 being inserted into the non-metallic clipreceiver 830. Continuing, FIG. 8E shows non-metallic clip 200 fullyinserted into the non-metallic clip receiver 830 joining firstnon-metallic member 810 to second non-metallic member 820. One ofordinary skill in the art will recognize that one or more non-metallicclips 200 may be used to connect two or more non-metallic members (e.g.,810 and 820), whose shape and size may vary, in accordance with one ormore embodiments of the present invention.

FIG. 9 shows a top plan view of a non-metallic clip and a bottom planview of a non-metallic clip receiver in accordance with one or moreembodiments of the present invention. One or more of the followingfeatures may be included as part of the clip connection system toprovide a zero-clearance interference fit that is pre-loaded and resistsrotation and extrusion under load.

In one or more embodiments of the present invention, at least twointernal angles (e.g., 910 a, 910 b) of non-metallic clip 200 and thecorresponding angles (e.g., 915 a, 915 b) of the non-metallic clipreceiver 410 may be different, resulting in a pre-loaded interferencefit between non-metallic clip 200 and non-metallic clip receiver 410formed from two non-metallic members 100 a, 100 b (or generic 810, 820of FIG. 8). As such, non-metallic clip 200 has a pre-load angle feature(e.g., 910 a, 910 b) that differs from a corresponding pre-load anglefeature (e.g., 915 a, 915 b) of non-metallic clip receiver 410. One ofordinary skill in the art will recognize that the angle or angles thatvary, as well as the magnitude of the difference in angles between clip200 and corresponding receiver 410, may vary based on an application ordesign in accordance with one or more embodiments of the presentinvention.

In one or more embodiments of the present invention, at least two largeradii (e.g., 920 a, 920 b) of the two longitudinal flared wing portions(e.g., 210, 215 of FIG. 2) of non-metallic clip 200 and thecorresponding radii (e.g., 925 a, 925 b) of non-metallic clip receiver410 may be different, also resulting in a pre-load interference fitbetween non-metallic clip 200 and non-metallic clip receiver 410 formedfrom two non-metallic members 100 a, 100 b (or generic 810, 820 of FIG.8). As such, non-metallic clip 200 has a pre-load radius feature (e.g.,920 a, 920 b) that differs from a corresponding pre-load radius feature(e.g., 925 a, 925 b) of non-metallic clip receiver 410. One of ordinaryskill in the art will recognize that the radius or radii that vary, aswell as the magnitude of the difference in radius between clip 200 andcorresponding receiver 410, may vary based on an application or designin accordance with one or more embodiments of the present invention.

In one or more embodiments of the present invention, non-metallic clip200 may have at least two rotation-preventing angle features (e.g., 930a, 930 b) on a distal end of the substantially rectangular base portion(e.g., 205 of FIG. 2) of non-metallic clip 200 and corresponding anglefeatures (e.g., 935 a, 935 b) of non-metallic clip receiver 410 thatprevent rotation under loading conditions. One of ordinary skill in theart will recognize that the number, location, and magnitude of theangles may vary based on an application or design in accordance with oneor more embodiments of the present invention.

In one or more embodiments of the present invention, non-metallic clip200 may have at least two installation allowance features (e.g., 940 a,940 b) that differ from the corresponding installation allowancefeatures of non-metallic clip receiver 410. For example, a width 940 aof the substantially rectangular base portion (e.g., 205 of FIG. 2) ofnon-metallic clip 200 may differ from the width 945 a of non-metallicclip receiver 410 to facilitate installation. Similarly, a width 940 bof the longitudinal flared wing portions (e.g., 210, 215 of FIG. 2) ofnon-metallic clip 200 may differ from the width 945 b of thenon-metallic clip receiver 410. One of ordinary skill in the art willrecognize that the type, kind, orientation, and number of installationallowance features may vary based on an application or design inaccordance with one or more embodiments of the present invention.

Once two non-metallic members 100 a, 100 b (or generic 810, 820 of FIG.8) that form the non-metallic clip receiver 410 (or generic 830 of FIG.8) are connected by non-metallic clip 200, some faces of non-metallicclip 200 and non-metallic clip receiver 410 (or generic 830 of FIG. 8)are perpendicular to the joining line or faces of non-metallic clipreceiver 410 (or generic 830 of FIG. 8) and are in extremely closetolerance and/or have an interference fit so as to prevent movement thatwould potentially result in the separation of the two non-metallicmembers 100 a, 100 b (or generic 810, 820 of FIG. 8) under load. Asloading increases on the two non-metallic members 100 a, 100 b (orgeneric 810, 820 of FIG. 8), the inside angles of non-metallic clip 200may transfer the load to the substantially rectangular base portion(e.g., 205 of FIG. 2) of non-metallic clip 200. In doing so, there is atendency for the longitudinal flared wing portions (e.g., 210, 215 ofFIG. 2) of non-metallic clip 200 to rotate about the radius on theinternal angle. This rotation is prevented by the angle feature on theoutside portion of non-metallic clip 200.

Advantages of one or more embodiments of the present invention mayinclude one or more of the following:

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system does not include any metal contentand is not subject to corrosion.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system uses a non-metallic clip connectionsystem that does not require coated metal fasteners or cathodicprotection.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system eliminates the need for specializedinstallation tools, including those that require specific torquesettings or installation procedures.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system requires fewer parts and is lessexpensive to manufacture than conventional vertebrae bend restrictors.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system is less complex and less expensiveto install than conventional vertebrae bend restrictors using bolts.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system reduces or eliminates lost partsduring installation because clips can be partially inserted with easeand held in place during shipment and while installation is underway.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system reduces or eliminates themaintenance associated with conventional vertebrae bend restrictors.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system reduces the number of componentsrequired as compared to conventional vertebrae bend restrictors.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system provide improved reliability overconventional vertebrae bend restrictors, end pieces, and connectionsystems.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system provide the same or improvedfunctionality over conventional vertebrae bend restrictors, end pieces,and connection systems.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system may be used in offshore energyapplications.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system may be used in onshore energyapplications.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system may be used in wind farmapplications.

In one or more embodiments of the present invention, a non-metallicvertebrae bend restrictor, a non-metallic vertebrae end piece, and anon-metallic clip connection system may be used in submarine antennaapplications.

While the present invention has been described with respect to theabove-noted embodiments, those skilled in the art, having the benefit ofthis disclosure, will recognize that other embodiments may be devisedthat are within the scope of the invention as disclosed herein.Accordingly, the scope of the invention should be limited only by theappended claims.

What is claimed is:
 1. A non-metallic vertebrae bend restrictorcomprising: a first non-metallic member comprising a first ball portion,a first socket portion, a first portion of a first non-metallic clipreceiver, a first portion of a second non-metallic clip receiver, and afirst cavity portion; a second non-metallic member comprising a secondball portion, a second socket portion, a second portion of the firstnon-metallic clip receiver, a second portion of the second non-metallicclip receiver, and a second cavity portion; a first non-metallic clip;and a second non-metallic clip, wherein the first non-metallic member issecured to the second non-metallic member by inserting the firstnon-metallic clip in the first non-metallic clip receiver and insertingthe second non-metallic clip in the second non-metallic clip receiver.2. The non-metallic vertebrae bend restrictor of claim 1, wherein alledges other than a top face of each of the first non-metallic clip andthe second non-metallic clip are beveled or radiused.
 3. Thenon-metallic vertebrae bend restrictor of claim 1, wherein each of thefirst non-metallic clip and the second non-metallic clip comprise asubstantially rectangular base portion, a first longitudinal flared wingportion, and a second longitudinal flared wing portion.
 4. Thenon-metallic vertebrae bend restrictor of claim 3, wherein each of thefirst non-metallic clip and the second non-metallic clip furthercomprise a clip retention feature disposed on a rear face of thesubstantially rectangular base portion near a top face.
 5. Thenon-metallic vertebrae bend restrictor of claim 1, wherein the firstnon-metallic clip fits in the first non-metallic clip receiver and thesecond non-metallic clip fits in the second non-metallic clip receiverwith an interference fit.
 6. The non-metallic vertebrae bend restrictorof claim 1, wherein the first non-metallic clip has a pre-load anglefeature that is different from a corresponding pre-load angle feature ofthe first non-metallic clip receiver and the second non-metallic cliphas a pre-load angle feature that is different from a correspondingpre-load angle feature of the second non-metallic clip receiver.
 7. Thenon-metallic vertebrae bend restrictor of claim 1, wherein the firstnon-metallic clip has a pre-load radius feature that is different from acorresponding pre-load radius feature of the first non-metallic clipreceiver and the second non-metallic clip has a pre-load radius featurethat is different from a corresponding pre-load radius feature of thesecond non-metallic clip receiver.
 8. The non-metallic vertebrae bendrestrictor of claim 1, wherein each of the first non-metallic clip andthe second non-metallic clip have a rotation-preventing angle feature ona distal end of a substantially rectangular base portion and each of thefirst non-metallic clip receiver and the second non-metallic clipreceiver have a corresponding rotation-preventing angle feature in thefirst non-metallic clip receiver and the second non-metallic clipreceiver.
 9. The non-metallic vertebrae bend restrictor of claim 1,wherein each of the first non-metallic clip and the second non-metallicclip have an installation allowance feature and each of the firstnon-metallic clip receiver and the second non-metallic clip receiverhave a different installation allowance feature in the firstnon-metallic clip receiver and the second non-metallic clip receiver.10. The non-metallic vertebrae bend restrictor of claim 1, wherein eachof the first non-metallic clip receiver and the second non-metallic clipreceiver have a supporting mass above an angle feature of the firstnon-metallic clip and the second non-metallic clip.
 11. A non-metallicvertebrae end piece comprising: a first non-metallic member comprising afirst socket portion, a first portion of a first non-metallic clipreceiver, a first portion of a second non-metallic clip receiver, and afirst cavity portion; a second non-metallic member comprising a secondsocket portion, a second portion of the first non-metallic clipreceiver, a second portion of the second non-metallic clip receiver, anda second cavity portion; a first non-metallic clip; and a secondnon-metallic clip, wherein the first non-metallic member is secured tothe second non-metallic member by inserting the first non-metallic clipin the first non-metallic clip receiver and inserting the secondnon-metallic clip in the second non-metallic clip receiver.
 12. Thenon-metallic vertebrae end piece of claim 11, wherein all edges otherthan a top face of each of the first non-metallic clip and the secondnon-metallic clip are beveled or radiused.
 13. The non-metallicvertebrae end piece of claim 11, wherein each of the first non-metallicclip and the second non-metallic clip comprise a substantiallyrectangular base portion, a first longitudinal flared wing portion, anda second longitudinal flared wing portion.
 14. The non-metallicvertebrae end piece of claim 13, wherein each of the first non-metallicclip and the second non-metallic clip further comprise a clip retentionfeature disposed on a rear face of the substantially rectangular baseportion near a top face.
 15. The non-metallic vertebrae end piece ofclaim 11, wherein the first non-metallic clip fits in the firstnon-metallic clip receiver and the second non-metallic clip fits in thesecond non-metallic clip receiver with an interference fit.
 16. Thenon-metallic vertebrae end piece of claim 11, wherein the firstnon-metallic clip has a pre-load angle feature that is different from acorresponding pre-load angle feature of the first non-metallic clipreceiver and the second non-metallic clip has a pre-load angle featurethat is different from a corresponding pre-load angle feature of thesecond non-metallic clip receiver.
 17. The non-metallic vertebrae endpiece of claim 11, wherein the first non-metallic clip has a pre-loadradius feature that is different from a corresponding pre-load radiusfeature of the first non-metallic clip receiver and the secondnon-metallic clip has a pre-load radius feature that is different from acorresponding pre-load radius feature of the second non-metallic clipreceiver.
 18. The non-metallic vertebrae end piece of claim 11, whereineach of the first non-metallic clip and the second non-metallic cliphave a rotation-preventing angle feature on a distal end of asubstantially rectangular base portion and each of the firstnon-metallic clip receiver and the second non-metallic clip receiverhave a corresponding rotation-preventing angle feature in the firstnon-metallic clip receiver and the second non-metallic clip receiver.19. The non-metallic vertebrae end piece of claim 11, wherein each ofthe first non-metallic clip and the second non-metallic clip have aninstallation allowance feature and each of the first non-metallic clipreceiver and the second non-metallic clip receiver have a differentinstallation allowance feature in the first non-metallic clip receiverand the second non-metallic clip receiver.
 20. The non-metallicvertebrae end piece of claim 11, wherein each of the first non-metallicclip receiver and the second non-metallic clip receiver have asupporting mass above an angle feature of the first non-metallic clipand the second non-metallic clip.